Interventions for Tuberculosis Control and Elimination 2002

• protection afforded by vaccinating adolescents or adults;
• protection afforded by vaccinating people of various ages.
Protection conferred by BCG vaccination against disseminated
and meningeal tuberculosis, and against death from tuberculosis
Five major prospective studies have looked into the protection afforded
by BCG vaccination against death from tuberculosis (figure 60). 736,738-744
All of these studies were conducted before the advent of curative
chemotherapy. Four of the studies showed a point estimate of the protective
efficacy of 80% and above, and one afforded no protection. The
confidence interval was wide in all studies, because the number of events
was small.
Several retrospective studies (including two using two different control
groups) examined the protection against disseminated and meningeal
tuberculosis (figure 61). 745-747,747-753 The protective effectiveness was usually
in excess of 80% and in no case did the 95% confidence interval
include zero.
N. Am. Indians
Chicago
Philadelphia
Saskatchewan
New York City
-400 -100 0 30 50 80 90 95
Per cent protection
108
Death
Death
Death
Death
Death
Figure 60. Results from five controlled clinical trials to evaluate the efficacy of
BCG vaccination against death from tuberculosis. 736,741-744